More fun with Microsoft

Adding a job to sql server via Sql Server Management studio might produce this cryptic error

Unable to cast object of type 'Microsoft.SqlServer.Management.Smo.SimpleObjectKey' to type
'Microsoft.SqlServer.Management.Smo.Agent.JobObjectKey'. (Microsoft.SqlServer.Smo)

You might try to try and install the latest Sql Server (AND Client tools) Service Pack, after a summary google search. In my case, it was simply a matter of using windows authentication versus traditional authentication. Don't use sa, use a Windows users with admin privileges (or the user the service manager impersonates running the server).

And remember, you've read it first here :-)